The present invention relates to a bottle which provides an emergency water ration and to a method for its manufacture.
A bottle used an emergency water container or as an emergency water ration is thrown into the water in rescue vessels from an airplane or from a ship and used on rafts and in lifeboats. Such a bottle is subject to high requirements. Packed in a rescue vessel, it must e.g. be adapted to be thrown into the water without damage from a height of at least 36 m, and it must further be resistant particularly to crude oil and salt water, and the content drinking water should have a lifetime of up to 5 years.
There are already known quite a lot of containers for water rations for the above purposes. On rafts or the like water rations are used in form of tin cans, in which the water is sterilized, and the cans are locked after disinfection. The drawback of such containers resides in that due to the influence of sea water the containers are readily subjected to corrosion, so that after a short time they become useless. Another disadvantage resides in that when they are subjected to mechanical action, for example when they are mechanically bumped, their double flanges or soldered seams or joints break open which results in a loss of the water. Also cylindrically shaped cans occupy a relatively large space, which is particularly disadvantageous in rescue vessels which are thrown into the water. However, to avoid such disadvantages, so-called "plastic packs" sometimes have been used. These are small bags made of a foil tube by first filling the tubular body with water and then welding and dividing it into predetermined compartments. Such water-containing and plastic-made packets have a content of about 100 ml. The material used for the tube is preferably polypropylene, and the filled packets are sterilized by exposing them to UV radiation. For sterilizing the water serving as the emergency ration it is also known in the art to use silver nitrate. However, such a disinfectant is often disapproved of, and in some countries only boiled water as an emergency ration is licensed to be used. Such small plastic-made packs which contain a relatively small amount of water have the disadvantage that they are not sufficiently resistant to mechanical influences such as occur when the pack is thrown down from a height of at least 36 m. Usually the packs burst whereby the water flows out.
It is therefore the object of the present invention to provide a bottle useful as an emergency water ration which when packed in a rescue vessel, is resistant to deformations and may be packed in a relatively high packing density. It is another object of the present invention to provide a method of making such a bottle containing boiled, sterilized water.
Thanks to its material and its particular shape the bottle used for housing the emergency water ration according to the present invention is inherently very stable. The highy density polyethylene is particularly suitable for the intended purpose. Aside from a comparatively highy compression and tensile strengths, polyethylene has an excellent stability within the range of atmospheric temperatures. Due to the fact that the bottle is made as a flat body and has an inclined front face including the pouring spout, it is possible to pack a plurality of bottles in a narrow space. The vaulted lower bottom and the arrangement of the feeder, which is displaced to one side of the upper bottom, serves to dampen the energy shock when the bottle hits the water surface after being disposed from a significant height and also prevents the neck of the bottle from being struck. The location of the feeder or pouring spout at one side of the bottle also serves for better handling of the bottle when drinking, so that e.g. in the case of heavy seas, no drinking water is spilled.
Another significant advantage is that the bottle has a locking plug which is also made of high density polyethylene and which has a conically shaped plug for engaging with the neck of the bottle and with a thread engaging in the thread of the pouring spout. Due to the inside cone of the locking plug the neck of the bottle is slightly expanded as the bottle is being locked, thus being securely sealed in that the thread is self-locking in this condition.
According to the present invention it is further proposed that both the locking plug and the pouring spout have a buttress thread. Such a particular thread had the advantage that after completed sterilization the screw cap cannot be blocked in such a way that the opening of the bottle is rendered undesirably difficult.
According to another proposal of the present invention both the locking plug and the pouring spout have a trapezoidal thread.
Another significant advantage is that the pouring spout has a flange, disposed below the thread. In the locked condition the lower ring surface of the locking plug is thereby slightly spaced from the upper ring surface of the flange. Such a design allows a shrink sealing of the screw cap of the bottle, for which purpose a shrink foil is applied to the locking plug and the flange, or the gap between the locking plug and the flange is sealed by a colored varnish.
Another significant advantage of the present invention is that the polyethylene is maintained free or organic dyes or the like. Thus, it is ensured that the material of the bottle does not secrete any substances which affect the taste of the water.
According to the present invention it is further proposed that in a lateral wall of the bottle there is arranged a transparent sight strip extending in the longitudinal direction of the bottle. Such a sight strip, which is preferably arranged in a narrow side, enables the filling level to be exactly read, while the filling level is not readily readable across the remaining portions of the walls which are not necessarily transparent. In order to provide exact reading the sight strip may be provided with an appropriate scale.
The radii of the of the inside edges of the bottle are rounded with a size of at least 5 mm, so that punctual loads, such as may occur when the bottle is disposed from a large height, can be avoided. Also the pouring spout is arranged on the inclined surface with radial transitions whereby the bottle also receives the required stability in this critical area.
According to another feature of the present invention, on one of the lateral walls of the bottle there is provided a text field with information given in friction-resistant raised letters. The raised letters may be pressed or milled in the lateral wall and comprises, inter alia, information on licenses and rules of respective countries for the water quality of the emergency water ration.
Despite the face that hollow products made of polyethylene of the above kind exhibit a high expandibility, the volume of the bottle is not completely filled with water. According to the present invention it is therefore proposed that only about 95% of the volume of the bottle be utilized. Thanks to the advantageous shape of the bottle the volume required for packing a filled bottle is only 20 to 25% larger than the bottle volume, to that the space available in a rescue vessel is very well utilized. The hitherto used water containers require more packing space for a comparable amount of drinking water.
The bottle is resistant to petroleum and to temperatures ranging from -35.degree. C. to 125.degree. C. so that the sterilization process may be carried out without damage to the bottle and the latter is ready for use under the most varied climatic conditions.
According to the present invention it is proposed that for preparing the bottle there is used a high density polyethylene free of organic dyes; that in the finished state of the polyethylene bottle is stabilized with UV light and that the bottle is then filled with water, locked and sterilized. It is an essential point that the polyethylene which is free of organic dyes or the like does not secrete any substances which affect the taste and quality of the water. For this reason the material of the finished bottle is once again sterilized with UV light to prevent traces of the materials contained in the polyethylene from passing into the drinking water.
The sterilization of the drinking water in the finished bottle is performed in a manner such that after the bottle is filled with filtered drinking water and locked, it is placed in an overpressure water bath heated to 120.degree. C. The duration of the heating is not critical, however, it should be at least 10 minutes. For sterilizing the water in the bottle the high inherent stability of the stabilized polyethylene of the above kind is particularly useful. As mentioned above, prior to sterilization the material of the bottle is stabilized so as to prevent taste-affecting components from passing from the material of the bottle into the drinking water. After cooling the bottle, which is done preferably by using compressed air, the bottles are marked, whereby particularly the date of filling and the date of ultimate consumption are placed beside the pouring spout of the bottle.
Due to the fact that the locking cap consists of the same material as the bottle, taste-affecting substances are prevented from passing from the locking plug into the drinking water. Further, the locking plug does not require any special sealing which would have to be highly resistant. It goes without saying that also the material of the plug will be stabilized with UV radiation after completion thereof.